SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '750b8128c8899d4beb82ad9547078a6b381c543b557e8a409f68739fa6040d40' 
  AND token = 'vwdU0/Gmn0IKOx/jtXzryx+QbsKGZZMHCl5d1z7X05s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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