SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47a9f85bea63dca953cd8daece5232c20e276b91c983b2c924c85fc5221184f6' 
  AND token = 'IJRmf7bxh9OliwXqwfapw9BXmjAQvoo7zmaEQnMDfj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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