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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67a42ea8fa7bcb2f62e763f2d4d40e1ea99ddd8cdbab7d2dd4d6acff43afd03a' 
  AND token = 'SpDb8ewHi4LBejqIpF+y4adsshUBDs5cZYieCVzssLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}