SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2f01ebd9c70c0935992908e51532227a8a3419d741ef81636487738d599e43b' 
  AND token = 'uy7Q8ZCz3DJ9FKnMBCBcapNOF6kgJHy5Z9HAbflzF9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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