SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ded5373a2ea287154f6e4a95d232edcd9feb660548c6dc0538f1a63293ba944' 
  AND token = 'TCDS5IJHmSCLZHomkbxNe6JSWVTmYuY1rJXAPI4+sSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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