SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4382c7f9421613cb395d530bbbba876214da57ee7311a8a7653fdb6f4f784f9a' 
  AND token = '8NVmQOlNw4IkCGZjt7mO8lA2AUF83wsfEpxjDnu6wN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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