SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c53dcae318a7acc00eb9f463ef61df7bbdbfe25c5cca7f613e405f4d2013ec4c' 
  AND token = 'sDNlC5rGej/sfi3iimGnJLXxja2TnC01AoJiayG8EyI=' 
  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"
    }
  }
}