SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '510d6928dd5b7d5228357bf721e283cc79f75bab36c07bfed7341050d8866516' 
  AND token = 'zA1SICz99fJjwvLEWEQMpa29OoLFWFMi9FNe6El0F20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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