SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93e07115578ed162637d4a10710ca919077e1011138c9bf39213b411bb72e8fd' 
  AND token = 'GUqXQugqjZ6UNOlKBG5HD5bVZ4TgCaugrBGbVpvtsqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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