SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43a7847943c21c1391683deae398ee7ed0e9f421d355f68f55889a93f19699de' 
  AND token = 'BsuriCeeur4LfdHY0Q7L6maF3PzXAcME/v/L7zp6fIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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