SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd560a238ddf93e83a46320ea4f873742b3705326aa92940a518fd537f6d5a3d1' 
  AND token = '1hYM2vtM7C5RMdWOZ2DbImnrcoie8Rbf/Kf3K/rqJGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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