SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3eda4126150f7df810633a6ac95491e6cd49cba96ee93153c8bdce8e9637d50c' 
  AND token = 'PaykUl9owgdfPBl5045rUaE078wUigy2xiFv49MNk1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}