SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f539a810fd3f26cee7812f10c4c8d8c83d9ac16ee9e974b6826d8514c307591f' 
  AND token = 'HA0B8He1MDah38mJpSGBjum/NpwJCDBWYFFkvgRXJCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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