SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '151fd9e3ae2418bbf0dd1f5ca137062c28f617f22aae5ea851705b31acf6c636' 
  AND token = '1CDmk4fHEOSv5cDrGOGddyxyqC6J9fTYnAsZiVpT2gw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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