SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '25c420b9ec7e7fcd4e1f25523caea438e9f48d34baa3a743153188d1f592052f' 
  AND token = 'jJqoS2C6//VnXQdMfBc7wPRBeXROgJp6nisz1uJ+KLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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