SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd704115d36a12a793b917b4ed7ddb1737097355a017331a63e1c7222a380236' 
  AND token = 'yPvxBAB7hKqE5TyYporhh6pfnu1VcYJuHn/HNmxWrow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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