SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a653a62ac628e5185ae126e8d8766b70aa27ff1cbc84e0103571dad8a6cbf7f0' 
  AND token = 'nky0JzYqRUjQ+dPm1OfVJU35qLKKn/bI8Ezk+uFRHE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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