SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bd0a0eb83ca0e0759a6892ef2b4e8fbc28ad70a3d4028149e11cb56f6dd56fd3' 
  AND token = 'hkb/xVqXTwRYX4yKYVK+0ZejYV7J1f2AMgT+5YK02c4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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