SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd86c6c2f9727406d8ba6bc5ba6de193208644a717ef57837ecb790b173b1b2b' 
  AND token = 'KWyK+uGRBjCGPZvwbPYLRn0QL9S83T9ZUJSBskRnrPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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