SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ee580b25b23307c2060f5638f37e452e76cac1efacadb237677a4ae0e54f961' 
  AND token = 'P9Np+MblAjXvy5yn3bOVVvY/2jlSlDvadbpK7lbDEE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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