SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ff39444df3cdf19f0f87bacea08ffe1c1cf90e32bc22167a6469870af2c673d' 
  AND token = 'SKMbz+3L7winkjcZTFHo5yRzCLYJvp2vDvoEYmYD2qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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