SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91d009ff587e8e8b3aa0db3db9d50f9c9fa2c333866cc5a4e5a713a779d46bef' 
  AND token = 'ikJpurqD7R7wNYW01gk3yXZfYglmUrHolrmQuARHb7g=' 
  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"
    }
  }
}