SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d917128041165ac528333ab7b4f942b5cabb63767f371e813a2640085feff8d' 
  AND token = 'OyN9oPQGZBztyhfxri5JWkDtit19LQY2yECCMiFYSPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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