SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f12ad9dec5a76013dd67bef08dccc06251c312167143f253b969624ea429a137' 
  AND token = 'WxTboFYHBeyl+Q4Aqy/mZZY1zkrFG7Nkl3Jk6n+ySsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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