SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fc0275d88cb99b814d92a3d99c5ea5a3e1c859d3c0f7e7b21fd220f764abb92' 
  AND token = 'Ar0Q8U3YjpBI/JSNXw8NlxkXVj8a6FhSZB/goK9oR0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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