SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8043c524010e25f5e264fde16df99b6e7c6acb24c4cc8512f81050a7b246604' 
  AND token = 'NqehtzQk8IpOTzGFqu3V9/uJ5ADpcM6w1jQddDqDpbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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