SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e176148099edcab49d419e94331da531dd99c608bc9d6527336149cdba213ce9' 
  AND token = 'gxFVDTps4MAS4qfpxl9Rs48OoZJywlFInG8SXQLektY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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