SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcd89b642da35aa606937d6384171936654ecdb6b9e35174fd66b414d781c94f' 
  AND token = 'FJ1QT4nmB9PNRH14y6ADwjM+yDZA8HT9k1S7Epnd8Yg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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