SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6345ff9a49b6ccfc9af557869b709620595ea0e0c4f99adaadbe7550d5f23cc' 
  AND token = 'D+we6tbkUJhviYAuHHJQQqKP0q60NlwsOXRrY9IZIko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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