SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c17dac749fc61eda5bea587fffe18c9de19ccd4b386175bf9e6d80ddb81506' 
  AND token = 'qNEV7i6UxcSJbCBpa8UhizRUgbMup+KtI823thqGM6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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