SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aac8af9401203d21accb79580b39dd02ecd103c4600a6a93650bf728ac2038fb' 
  AND token = 'gyTxJ+74dCVn9AdKP3LiDROrKw3lZgYYwstBqXjLJ6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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