SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e1d567929749ff9a0f4bf109dfe6d95e3efbd8202803c68d542f685d374ebaf' 
  AND token = 'ZbI017JHlKBkfqKqxLrGSzyIKZDDWvpwRIV6L3nu/RY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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