SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc9c5accfda9f19474ee91101af0a2241baf9132da4197062155e466d90edde3' 
  AND token = 'WNdn22pn71OUN/TIM01ZWSPyhg/eEzz2M+Dc39Vw0h4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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