SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a817c1019df9fdcd26903f27869f477abfedcfec5dcd61a2d370862d534fb26f' 
  AND token = 'yrp4ISilRDhRmYhHqi5ZmdB1dFwZPiMU6qoexEEiehw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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