SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5f3ea74b01f65356a219c38be9852e38c8303a6cf1a684444788c8cad3215a1' 
  AND token = 'fo3yvDHWo6SgAh625YbNeDtI1vUSXhKnaRNiXjryBzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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