SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d64066af62e157bbf50a54fcd3c6eb34584ca406ad461aada8ea79d70979c65' 
  AND token = 'N34X3VVf41ua12ivxlTf2qG8uMt4JB5g+6ykEjGVGxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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