SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f780b3fefab68afd9fabdf5e6d9995a1cab8202de1cd6731a905d94abf641871' 
  AND token = '+FcNhPMq5bqqpci9UjtuUG8UeTr1SCowH9lCx2utj/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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