SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9da64627a2bd85733737acbed06c561ce97d253a3558bd7110875ec974f40021' 
  AND token = 'AJwaota6iZZqyS+XgDOeGuEpBtLsKCpIaScjKyB9nI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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