SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '76dc273e989fc50d19bfee5890056169ca1eecc757b89fd90b6c8ce48ffef91f' 
  AND token = 'wUVveFVW+7HRG0KW05zp+/ia0Bp7GN1Mnppw5nxXUtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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