SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7b66fa95f48940dccaf264f1b8514a7a04cd98cb809d3edb58903e0c28ae375' 
  AND token = 'wbUcjn8MtySGxH/YME0b7BgLvPpeIyALTAE0iXFlodw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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