SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2845dc55e3ad01372528dedab527947479b0aa2f97522f2de415e8c7e0591bab' 
  AND token = 'gC2SzRsF7MlWaY63RHWHmbaNg/jiRrf2x2RfFaCdYTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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