SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e888f41ddbc715eaebca270cbbd4c9ee9019959e81144bb4655f9776459b28c1' 
  AND token = 'J8wgCTGYuJa4XQG/6VrzuPZl+l1qa+FPhfBNFcg411Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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