SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f6ca529613cb0382a10a8910be7746ae92a7bb8721e50f949365294aadb60cb6' 
  AND token = 'CqYwqqR0TkX8aWW1rZKRTN3hjFBwO6ODYwPA5eQmFok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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