SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd9928be249ad64d0577ab49a214bd408818e86164961ba529c4aa8d35ccceb4' 
  AND token = 'sIBuw2dufBZ3iufdAA30UlV8/8At3OUr7ys83UCo/BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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