SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd9d5c812632ebe98850f655e60224af62061936430a95b2ce3afe40ce3dec5b2' 
  AND token = '6lzzB0qVycMszsdOtnk0rw+PYxhjZ8uyZsAbjg7wveQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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