SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4299608875f6ac7606bfe10598f3e1ea51e21dbba8a122a5afd5650f725e864' 
  AND token = 'Crh/ZV3tg82BBq+DYVwaQ2R4NCZXAHKOACa33yIIu/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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