SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0b2db53cb865d11cc6223aacc9db677315da73798349ce31ac0bca22a3be745' 
  AND token = 'w8uJ+w3PCSdOEKgmAJgonISImp9Atzy9flTjJF66YEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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