SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '803ae9ff886925619db64c942b202f5a89fd75d973f4f7d7f36466b0bd251bad' 
  AND token = 'qMZOj+vagv4GpIhEQ7ztiwedXTTy7f6k9i7/A/NV8Nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00112

JSON explain

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