SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93c443ee01e385a7eee42a92a8182f8e1abe55ce5a8325fb7a54e15fe0212d1f' 
  AND token = '8yFWVd3GghO92ULFfwgsGD4AJ4XsWOxROf0UMWyzy3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}