SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45d8238d4ca3cb9be1f6655aa0eac22cc79531c1c48eacbc2d17c00ddb701e31' 
  AND token = 'cOpxTHHlHLevgubRmVbyMe+0lzAYnx+bgdHL+TUhHVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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