SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24936dade61caf19e5910822d1479cf317b59f0ab1b25889755c6cefb3159a62' 
  AND token = '1v3LEPW5e6q3BZhJIbKMkYDoDVBj2W+MciB+6qhWThA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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