SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe835e89d7cb0a62ed44a32af8b027d7c4b39857f4a3e280a09b2dfbf96a5289' 
  AND token = 'ym5/RuVh7C5ExmvGPIOGZBLbCuhdKtqaypJXMx6d02U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00076

JSON explain

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