SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8de76f9fcc90bc460d147c3acf58e66d9e1d381ed98ae73d871ec297d4857b2d' 
  AND token = 'zT139bpn6Bkh4ZGeoiVbh6jPyEVlqWaAYeywNMzKv9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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