SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e461768ba8e03ea979146960b61ae9ca02decdb5300dc73af49d3fb28d15ff90' 
  AND token = 'dDWv33kDQEHgZWpCOcgqLM6EDwplSBNCYMdqMe5M+qM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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