SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '867117c85ab2561db10afb66de084431db69d99ee1951290cffb07a5355f3490' 
  AND token = 'DcNbnKxKtvdJmP54AM0qU9alhp9M/9MSUbs9rvLfbuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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