SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7b18d5da5fecc3496b04dddcc4cf0eeb704b3810097cce44800ed3cba080ba9' 
  AND token = 'nTTU9D4NmIBs5tlIX/acs6BW+s9ciTE7F1HNWX8QwxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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