SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3a0c94ac42c0b8bfed264abc93a9adbc507ddd7fd3d0da89e3834d234b62ffc8' 
  AND token = 'yW5Qhhb4mF4m8ufQwEpfbENOxER/+EHvmJHvhHOiluI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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