SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe7a2395f20d475cb6aeb9096dfbdf4f2817b961ab2cf24ad02c09fabef9b960' 
  AND token = '1XNdjPna807Fx98TjDIzIj+xPmO+IfjUxvAXAq1bAng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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