SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fda0dd6c718b3fc5973a2eaa8ccb2fc70899047b2e8df26fdc49ae20984367c' 
  AND token = 'f0HNW5cAwwwDc9uVPFKgokKIAnYkkPec8ghPIX7OqkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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