SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cac9f696a584505c306f4f0703797de44b31b1c6e662724510f71b5df3fadbb0' 
  AND token = 'zxB5GIL/U2DUcKp+jRCiOe1YUjqkRAZodicuIqb0dmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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