SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6ec59297edc3a28104f483bc964750235d7bf79a92d8251055c19ca42888e41' 
  AND token = 'GgMV8imj0yHul5CaUjc2ZIERVPXKzQgQ5cpnSu3l5h0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}