SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '403aef68bf27f5162062efd3e28a17539034d1d5b8ecf539e6b64fae2637c106' 
  AND token = 'weo6FSYpxNizQnmNFdmttzVMopKwv/xyr16G2hKlTsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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