SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd91f735f46c441b9db619eb93ebaf2cc28256cb000c048abac97132ccd99245' 
  AND token = 'QLPoNhBeugK1LNf1kcl6YG1+aV1mrRUWt4J+hs2SPtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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