SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18fe9e39b821cdc8e3a785bac09d77b41b7f82e5a933b87587db0976a6924240' 
  AND token = 'Cbw9z/XA3BEgFISHSXiMBrEdPsVe6p9pGsdtf7zKHzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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