SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '87c5250e831da9c6550682b814b0a2274a9579635df1d9a0e1796968ebe3c6e7' 
  AND token = 'VrZ76vnzSwqr0vxTF81coX6MAb7qnuTpLNZ5lv4ZZUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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