SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1810dfd5b5edf2575e01cb2db1454fdb00f57b3e891562edaa6f2c45fc556733' 
  AND token = 'NJwVaEjeUcNSvqVqicKf/EoMmqnNA2jJLIndRHQ/eYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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