SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63924949fd38c3360d3b447136ac7a5fb6a18f3e17677b6d42fe2bbaa04c06f6' 
  AND token = '3uUOEo9Eh0B2YnZTXoK+GdCsjOl5pubkxGsyxKfg8lY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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